Rasulullah wept whenever he was foretold the tragedy that would befall on Husain (a.s.) and his companions

We read in Fadhail Sahaba by Imam Ahmed, volume 2 page 965 Hadith 1357:

The Prophet (s) said: ‘An angel that has never visited me before, entered my house today and said to me: ‘This son of yours will be killed. If you wish, I can give you some soil from the earth wherein he shall die’. The Prophet (s) then said: ‘The angel brought to me soil that was red’’.

In the footnote we read:

The chain is Sahih. He (Ahmed bin Hanbal) has brought this Hadith in his Musnad as did al-Haythami in Majma al-Zawaid and has said: ‘Ahmed has recorded this Hadith and its narrators are Sahih and Tabarani has recorded this Hadith from Ayesha with a Sahih chain. And in Majma al-Zawaid it is mentioned: ‘Ahmed has narrated this as have Abi Ya’la and Tabarani and Bazzar and its narrators are all Thiqaat (truthworthy).
Fadhail Sahaba by Imam Ahmed, volume 2 page 965 Hadith 1357

Musnad Abi Ya’la Al-Musili, Volume 1 page 298 Hadith 363:

Abdullah ibn Naji narrated from his father who said: ‘I went with Ali, they faced Nainawa as they were going to the battle of Siffeen then Ali called out and said: ‘O Aba Abdullah, have patience, O Aba Abdullah have patience on the bank of the Euphrates’. I asked: ‘What do you mean by Aba Abdullah’? Ali replied: ‘One day I went into the room of the Prophet (s) whilst his (s) eyes were gushing with tears, I therefore asked of him: ‘O Prophet (s), has someone angered you? What makes your eyes gush with tears?’ He (s) replied: ‘Gabriel has just left me; he (Gabriel) told me that Hussain will be killed on the banks of the Euphrates river. Gabriel then said to him (s): ‘Shall I let you smell its soil (wherein Hussain will be killed)? I said: ‘Yes’. So Gabriel extended his hand and presented a handful of the soil and gave it to me, I was then unable to prevent my eyes from gushing into tears’’’.

Hussain Asad Salim said:

‘The chain is Hasan’. Haythmani has recorded it in Majma al-Zawaid. Ahmed also has narrated it as did Abu Ya’la and Bazzar and Tabrani and the narrators are Thiqaat (trustworthy).
Musnad Abi Ya’la Al-Musili, Volume 1 page 298 Hadith 363

We also read in Musnad Abi Ya’la Al-Musili, Volume 6 page 129 Hadith 3402:

Anas bin Malik said: ‘The angel of rain asked permission from his Lord to visit the Holy Prophet (s) who granted permission. On that day the Prophet (s) was with Umme Salamah. The Prophet (s) told her: ‘Guard the door and do not let anyone in’. While she was at the door, Hussan bin Ali burst into the room, so the Prophet (s) began to hug and kiss him. The angel said to Prophet (s): ‘Do you love him?”. He (s) replied: ‘Yes’. The angel said: ‘Your nation will kill him. If you wish, I can show you the place wherein they will kill him’. The Prophet (s) said: ‘Yes’. So the angel took a handful of soil from the spot of his (Hussain’s) murder and showed it and it was Sahla or red soil’. So Umma Salamah took the soil and put it in her clothing’. Thabit said: ‘We would say that the sand was from Karbala’.

Hussain Asad Salim said: ‘The chain is Hasan’.

In Musnad Ahmed it is recorded: ‘The angel struck his hand and brought red sand’.
Musnad Abi Ya’la Al-Musili, Volume 6 page 129 Hadith 3402

Imam Ibn Habban has also recorded this in Sahih Ibn Habban, Volume 5 page 142 Hadith 6742. Al-Haythmai in Majma al-Zawaid, Volume 9 page has recorded a number of traditions wherein we read that Umme Salamah preserved the abovementioned soil in a bottle with her. Al-Albaani records a ‘Sahih’ Hadith:

Gabriel came to me and informed me that my Ummah will kill my son Hussain. I asked: ‘This Hussian?’. He (s) replied: ‘Yes’ he then brought me some of its soil that was red. Narrated by Umm al-Fadhal bint al-Harith that she went to the Holy Prophet (s) and said: ‘O Prophet (s), I have seen an unclear dream tonight’. He (s) asked: ‘What is it?’ She replied: ‘I saw that as if a part of your body was cut off from you and was placed upon my chest’. He (s) said: ‘You have seen something good. Inshallah Fatimah will bear a baby boy and he will be upon your chest.’ So Fatima gave birth to Hussain and he was on my chest as the Prophet (s) had notified me. On one day I went to the Holy Prophet (s) and put Hussain on his chest then he turned his face to the side and I witnessed his (s) eyes flowing with tears. I asked: “Prophet of Allah (s), may parents be sacrificed for you, what is wrong?” he (s) then mentioned it (the above hadith).
Silsilah Al-Ahadith Al-Sahiyah, Volume 2 page 462 Hadith 821

We can see from these traditions that Rasulullah (s) was foretold about the martyrdom of Imam Husayn (as) on four separate occasions, by three different angels. Upon being notified of the tragic demise of his grandson, Rasulullah (s) broke down into tears, distraught at what was to become of him. On none of these occasions did Rasulullah (s) appear impassive and motionless at the news, his emotions overtook and his eyes were filled with tears when he was notified of what harm would befall his grandson (as). If Rasulullah (s) cried so profusely at the news of what was to happen to his grandson in the future, can one imagine his state would be on the Day of Karbala, when Husayn (as) was showered with arrows, his head decapitated and horses trampled over his body? This proves that crying when hearing of the suffering of Husayn (as) is a Sunnah of Rasulullah (s).

The tradition can also be read in:
Sawaiq e Muhirqah, page 641